Review Question - QID 203012

Monoarticular arthritis is a common late manifestation of untreated Lyme disease, and positive serologies for B. burgdorferi can be helpful in establishing the diagnosis.

Lyme disease is the most common tick-borne disease in the United States and is seen mainly in the Northeast. It is caused by B. burgdorferi, a bacteria carried by the Ixodes deer tick. The most common early manifestation of Lyme disease is erythema migrans, a characteristic target-shaped skin lesion at the site of the tick bite, while later manifestations include neurologic symptoms, carditis, ocular findings, and arthritis.

Wright et al. discuss diagnosis and management of Lyme disease, and recommend that while culture is the diagnostic standard, it is not commonly performed due to its overall lack of availability. Instead, they recommend serologies using ELISA initially, followed by Western blot to confirm the diagnosis.

Smith et al. discuss the treatment and prognosis of Lyme arthritis. They present a treatment algorithm (Illustration A) and suggest 4 weeks of oral doxycycline or amoxicillin as first line therapy. Patients who remain symptomatic despite sufficient antibiotic treatment may require surgical intervention.

Illustration A is a treatment algorithm for Lyme disease.

Incorrect Answers:
Answer 2: MRI may be useful in evaluating trauma to the knee, which the patient denies.
Answer 3: Blood culture may be useful in the diagnosis of septic arthritis, but the patient’s presentation is not consistent with septic arthritis.
Answer 4: HLA-B27 is associated with Reiter’s syndrome.
Answer 5: Suspicion for gonococcal arthritis requires workup for other sexually transmitted diseases, but these are not as likely as Lyme disease given the history.